Hierarchical control of Hybrid Power Systems

This paper presents a hierarchical controller for a DC bus configuration hybrid power system consisting of a wind turbine, photovoltaic panels, a battery bank, capability for connection to grid, and load. The proposed hierarchical control system consisted of lower level controllers for each generation and storage component designed using sliding mode control and a supervisory controller that had the objective of maximizing use of the renewable sources while minimizing connection to the grid. The supervisory controller changed sliding surfaces and set points according to the operation conditions and performed load shedding based on load priorities when available generation is insufficient. The functionality and performance of the system is studied by means of simulations. The paper will present HPS model development, hierarchical controller design, and simulation results under the different operating scenarios. Simulation results show that the proposed controller has the capability to meet the design objectives with acceptable performance.